<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <!-- 动画转换   transition 1s all ease  -->
  <style media="screen">
    .box {
      width:300px;
      height:300px;
      background:#CCC;
      margin:10px auto 0;
      transition:1s all ease;
      transform:rotate(0deg);
    }
    .box:active{
      transform:rotate(90deg);
    }
  </style>
</head>
<body>
<div class='box'>这是一些文字</div>
</body>
</html>
